Bell tone generator



Nov. 12, 1957 J. T. KUNZ BELL TONE GENERATOR Filed Dec. 4, 1955 United States Patent O BELL TUNE GENERATOR Jacob T. Kunz, North Hills, Pa., assigner to Schulmerieh Electronics, Incorporated, Sellersville, Pa., a cnr-poration of Pennsylvania Application December 4, 1953, Serial No. 396,212 1 Claim. (Cl. 841.14)

This invention relates to electronic musical instruments, especially those having means for producing bell or chime tones.

Prior instruments of the type involved herein have used bars or rods, both solid and hollow, and other types of vibrating bell elements for the purpose of generating vibrations. Mechanical-electrical pick-ups have been employed, the electric vibrations then being amplified, modified, and reproduced by a loudspeaker so as to obtain the desired bell tone or tones. There has been considerable difficulty in many of the prior instruments to obtain the desired partials in their correct relationship, strength and duration in order that a pure bell or chime tone can be produced in the loudspeaker.

One of the objects of the present invention is to provide an improved mechanical-electric pick-up combination with a tone generator for producing bell tones.

The terms "characteristic tone or note are used herein to mean the sound sensation by which the listener identifies the pitch of the note involved. Fundamental is used to mean the lowest vibration actually present in the vibrator. ln an instrument of the type concerned herein, when the rod is struck so as to be set into vibration in a particular pattern, a person listening to the note produced as a result thereof will select the characteristic tone which identifies the pitch. In the case of a fixed free rod, the -characteristic tone has been found to be a synthesized tone not actually corresponding to a vibration of the rod, it being formed by a combination of the 4th and 5th partials of the rod. The invention herein is an improvement over that illustrated in Patent 2,582,441, January 15, 1952. In said patent, the tone generator comprises a fixed-free rod fixed to a relatively small supporting block in a manner to isolate the acoustic system. It has been found that it is desirable under sorne conditions, that all of the parts, including the collector plate, be mounted on the block in a manner so as to be acoustically integral therewith so as to prevent any spurious vibrations entering into the system.

These and other objects, advantages and features of the invention will become apparent from the following description and drawings.

In the drawings:

Fig. 1 is a side elevation of a tone generator, the supporting elements being fragmentarily shown.

Fig. 2 is a sectional View taken along the line 2-2 of Fig. 1.

Fig. 3 is a schematic block wiring diagram.

The invention is described in conjunction with a single bell element tone generator but its principles can be applied to electronic carillons and other instruments having a plurality of vibrating elements.

Fixed-free rod is in the form of a flat strip of suitable metal of the correct length to provide vibrations to produce the desired characteristic tone. Post 11 is firmly secured to support block 12, post 11 having a slot therein (not shown) snugly receiving the fixed end of rod 10. As an example, the edges of the slot can be pressed inwardly so as to make the joint between the rod and post acousticaily integral. Steps also should be taken so as to insure that the post is acoustically integral with the supporting block. The supporting block 12 is relatively small in contrast to massive blocks of some prior devices, and can be mounted on rubber bushings 13, 13, said bushings being held on cross bars 14 of the instrument. Cross bars 14, 14 in turn can be carried by frame members fragmentarily shown at 15A.

The condenser type microphone electric pick-up arrangement in conjunction with the above combination is the particular feature of this invention. It may take the form of a rigid rod 15 having a flared portion 16 appropriately spaced from the fixed free rod 10. An aperture 17 is provided in supporting block 12, said aperture having a circular plastic collector holder 18. The collector holder 18 may be of some suitable insulating material such as polystyrene or the like. It is dimensioned so that the upper end thereof tits tightly into aperture 17 of the supporting block 12. The shank of the collector may lbe screwthreaded so as to engage the threads 19 in an aperture through the collector holder 18. The threaded connection must be tight so as to firmly hold the collector. The lower end of rod 15 may have a slot 20 therein for the purpose of adjusting the position of the upper end 16 relative to the rod 10. A lock nut 21 may be located on the rod or collector 15 for the purpose of holding the collector rod in its adjusted position. The striker can be located on the opposite side of the supporting block in any suitable manner so as to hit the rod when energized in the correct location to produce the desired vibrations. Also the supporting block can be reversed (not shown) so yas to be above the striker.

In one manner of operation, an amplifier 22 (Fig. 3) can have one or more bells or tone generators, as illustrated in Fig. 2 connected thereto. The amplier also may have if desired a microphone and a record player which can be selectively connected to the amplifier. Loudspeaker 23 receives the amplified tone having the partials in the correct relationship. In order to properly damp the various partials without frequency selectivity, a flexible element 24 can be located in an aperture in the end of rod 10.

It is to be understood that variations may be made in the construction without departing from the spirit of the invention except as defined in the appended claim.

What is claimed is:

In a bell tone generator, the combination including a fixed-free vibrator bar adapted to be selectively set into vibration, an individual support block for said vibrator, a post carried by said block, said post and vibrator being firmy connected in acoustically integral relationship, said block having an aperture therethrough, resilient means for holding said support block on a frame, a solid material insulating collector element holder mounted tightly in said aperture in the support block `and in acoustically integral relationship thereto, said holder having a hole therethrough, and an electric pick-up collector element comprising a rigid rod member tightly mounted in said hole in the collector element holder so as to be rigid relative to said support block, said rod having a surface in electrical capacitive relationship to said vibrator bar, said vibrator bar, support, collector and post vibrating as a unit when the vibration is struck.

References Cited in the le of this patent UNITED STATES PATENTS 2,200,718 Miessner May 14, 1940 2,318,936 Fisher May 11, 1943 2,321,366 DeMuth June 8, 1943 2,582,441 Kunz Jan. 15, 1952 

